The first step in learning to play the guitar is buying the instrument itself. This can be quite a difficult process as someone who can not play the instrument is obviously not in a very good position to know what to look for when purchasing one. The situation is comparable to buying a car without being able to test it because you can not drive. Such a person is an easy target for unscrupulous salesmen and/or may choose the instrument based on the wrong criteria. I have had many students show up for their first lesson with a poor quality guitar for which they had paid too much or with a guitar that does not fit their body. They could have saved hundreds of dollars had they contacted me before purchasing their instrument. The instrument itself may hinder their ability to learn to play and be a source of frustration. Your first guitar will be something that you will play for hundreds of hours so it is crucial to find an instrument that you enjoy playing.
While this article is intended mostly for first time or inexperienced buyers it does contain a lot of information that is useful for more experienced guitarists. If you do not have time to read each page of the article I would recommend at least reading the last two pages, How to Decide What Type of Guitar to Buy and Recommended Brands.